Stuart Ross
Taylor
Professor Emeritus
The Australian National University

7:30 to 8:30 p.m.Friday January 25

Are We Alone in the Universe?

This question has been around for 24 centuries since it was first
raised by the Ancient Greeks. During the past 40 years, the exploration
of the solar system has provided much new evidence about the origin and
evolution of our planets and of the formation of the Earth. The recent
discovery of over 60 planets circling other stars has now told us that
other worlds exist. In this talk, I will discuss the origin of the Earth
and of our solar system. Then I will compare the extrasolar planets with
ours to see whether planets like the Earth, capable of supporting
intelligent life, are likely to be common or rare in the universe.

Prof. Ross Taylor is a world renowned geochemist and planetary
scientist whose recent research interests include the origin and
evolution of Earth's continental crust, the origin of the Moon, and the
formation and early evolution of the solar system.Among his many scientific accomplishments was to perform the
first chemical analysis on lunar rocks as part of the Apollo 11
Preliminary Examination Team.He
has received both the Goldschmidt and Leonard Medals, the highest honors
in the fields of geochemistry and planetary science, respectively, is a
Foreign Associate of the United States National Academy of Sciences and
has had an asteroid named after him.He has published 225 scientific articles, on a wide range of
topics in geochemistry, cosmochemistry and planetary science, as well as
eight books.His recent
book, "Destiny or Chance:Our Solar System and Its Place in the Universe", was
also published as a "books on tape" by Orion Audio Books.

New high resolution digital elevation models make it possible to view Long Island without buildings, roads, or trees. In colored-enhanced images a variety of geological features including ancient stream valleys can be clearly seen. Some valleys along the north shore of Long Island are tunnel valleys formed by streams traveling under the glacier. Most of these valleys are not presently occupied by streams, but are used as pathways for roads and highways. A spectacular example is the tunnel valley in Port Jefferson with the high valley walls on either side and with Main Street along the valley floor. In this case the water traveled uphill under the glacier exiting the glacier near the Port Jefferson Railroad station. The water in the stream was under a high hydrostatic pressure and may have drained a subglacial lake. As a result it was very effective at eroding the underlying sediment. This extensive erosion formed a valley at least 200 feet deep in places. The fast moving stream would have had a high sediment load. As the stream exited the glacier the sediment deposited from the stream formed a large fan of sands and gravels to the south.

In central Long Island two large valleys cut through the Ronkonkoma
Moraine. The one to the east is up to 2.5 miles wide and is presently
used by the Carmans River that flows to the south. The western valley is presently
used by both
the Nissequogue River that flows to the north and the Connetquot River
that flows to the south. The origin of these valleys is not known, but
they may have formed during the last glaciation
when a
large lake between the glacier to the north and the Ronkonkoma Moraine
overflowed the Ronkonkama Moraine forming deep, wide valleys. The
outwash plain south of the Harbor Hill Moraine is cut by a number of
abandoned stream valleys in which former streams drained to the two
large valleys. The outwash plain south of the Ronkonkoma Moraine
is cut by many abandoned stream valleys heading
southward. Near the south shore these ancient valleys commonly have streams in
them.

The evolution of the Earth is a vast process lasting
billions of years, involving huge amounts of matter (crystalline and
molten silicates, metals, and volatile constituents), temperatures from
near absolute zero to several thousand degrees, and pressures from a
vacuum to millions of atmospheres. Despite this complexity, the present
state and evolution through time of the Earth from its surface to its core
is governed by the laws of physics and chemistry. Phenomena on the
molecular scale (the atomic structures of minerals, silicate melts, and
volatile-rich fluids, and the bonding of the atoms within them) control
processes on the regional scale (earthquakes, volcanic eruptions) and on
the global scale (formation of the metallic core of the earth, plate
tectonics, subduction).

Understanding
of these phenomena requires direct studies of the Earth itself through
seismology, geology, and modeling.However,
understanding of the physical and chemical properties of the materials
that make up the earth is key to linking all of the observations.Recent federal investments in National Laboratories now yield tools
that enable us to probe material properties that are contained in high
pressure – high temperature devices in order to unlock the secrets that
help unify our vision of the Earth.This
lecture will describe these new tools, discuss the new style of
high-pressure experiment, and illustrate some of our new insights into the
Earth that have been gained.

Distinguished Prof. Weidner’s
research interests focus on mineral physics and seismology. The ultimate
goals are to combine these areas to help define the physical and chemical
state as well as the dynamic processes of the Earth's mantle and crust. He
is currently director of the Center
for High Pressure Research and the Mineral
Physics Institute.

Earth’s sedimentary rock record is a rich
archive of its past history. It is our only window into the evolution of
life, and of our changing climate system. Catastrophic events such as
proposed in the popular “Snowball Earth hypothesis” where the Earth
may have been completely frozen, and the demise of the dinosaurs are
some of the snippets of history recorded in the sedimentary rock record.
One problem with interpreting this history is the time factor. Many
geologic time boundaries have uncertainties that are greater than the
intervals they bracket. Our research shows that some of the very same
sedimentary materials that are used to reconstruct past conditions may
also be dated precisely using the U-Pb isotopic clocks. I will discuss
the challenges involved in selecting logical materials for dating and I
will discuss some controversial results that challenge the notion that
time boundaries based on fossils occurred at the same time on a global
scale.

In-service credit available for teachers

If your school requires that you have a
sequence of educational opportunities in order to receive in-service credit,
please advise them that during the Spring Semester we will be offering one-hour
of in-service credit for each of the: